What is Steganography?

Hey I'm really glad & excited to see this discussion here.
Because the Mini Project I did in the last semester was a "Key Protector" based on stagnography.
Actually Stagnography is a technique used to hide a small piece of confidential data with in a large data file.
For eg:- Hide a key phrase inside a bitmap picture file.
Even after the 'key data' is stored in between the color data in the bmp file the picture will look still the same to ur eyes.
What appear to be a silly cartoon or like a simple picture may actually be containing some potentially important piece of information. Like a pass word or an important date fixed for a secret experiment or operation.
I'll try to post a sample picture which has such a piece of data embedded in it by our software.